1. Field of the Invention
The present invention relates to a signal processing apparatus which processes a signal obtained from an image pickup element including a plurality of pixels that share one microlens.
2. Description of the Related Art
Previously, an image pickup apparatus which performs focus detection based on a phase difference between two pupil-divided images obtained from an image pickup element including a plurality of pixels that share one microlens has been known. Japanese Patent Laid-open No. 2001-83407 discloses an image pickup apparatus having an image pickup element including a plurality of pixels that share one microlens. The image pickup apparatus disclosed in Japanese Patent Laid-open No. 2001-83407, with performing focus detection based on a phase difference between two pupil-divided images obtained from the image pickup element, generates an image signal using an added signal (added electric charge) from the plurality of pixels that share one microlens, thereby obtaining an image output of high quality.
However, the image pickup apparatus disclosed in Japanese Patent Laid-open No. 2001-83407 cannot perform highly accurate focus detection when each of the divided pixels is saturated.